1. Technical Field
The present invention is directed toward window locks, and more particularly toward sash locks.
2. Background Art
Window locks are known in the art and generally include a catch with a handle operator affixed to a window frame or jamb which interacts with a keeper on a corresponding section of a movable window sash to securely hold the sash tightly against the frame. Also known in the art are devices for sequential multipoint lock-up of the movable window sash with the window frame. These latter devices are locks which have a handle actuator interacting with a keeper at one point on a window frame and sash respectively which causes a second lock to engage a keeper at a distant location.
It has long been a desire that such locks be aesthetically pleasing, particularly in view of their positioning adjacent the outer edge of windows, which usually serve as visual focal points in any room. Therefore, such locks have often been designed to provide minimal intrusion into the field of vision provided by the window. However, it must be recognized that as less visual attention is directed to the lock, the risk that the lock might inadvertently be left open is increased. Therefore, it is desirable to provide such desired aesthetics without decreasing the practical safety and security intended to be provided by such locks.
Further, such window locks are often used in windows which also have operators which may be used by an occupant to open and close the window sash. In some cases, separate locks are provided and must be manually manipulated by the occupant separately from the operator. In other cases, combination structures have been provided whereby operation of the operator will also sequentially operate the locks. Such combination structures require mechanical connections between the operator and the lock, with such connections varying in complexity and expense. Several such structures are shown in commonly owned U.S. Pat. Nos. 4,497,135, 4,617,758, 5,054,239, and 5,152,103 as well as U.S. Pat. Nos. 27,119, 1,724,011, 1,748,662, 2,114,645, 2,136,812, 3,257,755 and EPO Application No. 323,241. Still other structures which have attempted to combine control of windows (or other closures) with locking of those windows, again with varying expense and mechanical complexity, have been shown in commonly owned U.S. Pat. No. 4,937,976, U.S. Pat. Nos. 2,538,980, 3,081,078, 3,145,988, 3,154,302, 3,202,414, 3,274,732, 3,653,154, 4,333,269, 4,860,493, West German Patent No. 1,176,021, German Patent No. 653,755, and Poland Patent No. 43,872.
Still further, it has previously been considered to provide locking structures which are not operated manually by an occupant of the room, but rather are operated by an electric motor or the like. For example, previously mentioned commonly owned U.S. Pat. No. 4,497,135 discloses an automatic operator and locking mechanism which is operated by an electric motor. However, it should be recognized that since there is no "hands-on" control of the mechanism by an individual, it might not be so easy for the occupant to recognize if the lock does not operate correctly or perhaps breaks during operation. In such a case, the occupant would have a false sense of the security being provided by the lock until such time as he somehow discovered the improper operation and/or broken component.
Also, in some windows (particularly larger size windows), it is desirable to provide multiple locks to ensure adequate locking of the sash to the frame. One such structure for providing such operation is shown in commonly owned U.S. Pat. No. 4,991,886. That device uses a slider connecting two spaced apart catches which can interact with keepers affixed to a window sash and linked together by a tie bar structure to establish a locked condition of the window. The movement of a handle actuator from its unlocked position causes an adjacent cam member on a catch to connect with a planar portion of an associated ramped keeper. The movement of the catch causes the slider, which has a length of movement along a path between the two keepers, to move the second cam member onto the planar section of the associated ramped keeper. Such multipoint window locks are somewhat limited, however, insofar as the tie bar interconnection imposes restrictions on the window frame configuration as well as limiting the relative positioning of the individual lock members.
The present invention is directed toward overcoming one or more of the problems set forth above.